how to deal with the 0.8mm FBGA package

[fangll]

fbga package issues

How to place the bypass capacitor and route the trace for 0.8mm pitch FBGA MCU(271 pin).
I can not put 0.1u capactor under the each power pin (0402 package) because of very small size of the FBGA package chip.
Can anybody give me some advice on how to deal with such package for PCB design, such as wire width, via size,...

 

[Sukohi_Berkut]

trace recommendations fbga

hi

it depends on what kind of board,

a 0.8mm bga is a bad idea for any design

expect,

1. a shit load of cross-talk
2. DFM and DFA issues
3. High price tag for manufacturing

you cannot place a 0402 package between those pins,

you can do that provided,

1. use blind and burried via
2. drill over the bga pad, upto certain layer.
3. use drill size from 6-8 (be careful if your board is more than 100 mil thick this won't work, the aspect ration is 1:8 for tight design and 1:10 for high yield FAB)


its going to cost you dearly and a lot of trouble.

Intel dsicontinued their 0.8mm flash just for that reason.

but if you are ready for spending lot of money and you are ok with high-end fab process, you should use the above said recommendation.

use 20mil/20mil pad and 20 mil airgap between the 2 pads for the land-pattern of 0402

even doing all these, it is very tight low-yield FAB process and absolutely no rework.

ask your FAB vendor and have a meeting with them

discuss with them the all the options and design your board with an OKAY from them,

it will be very painful to know that your FAB vendor cannot do the board when it is too late, that is after you complete ur board

best of luck
regards